refactor: repl prompts are now the job of the interacter

NixOS · Feb 26, 2024 · 7abbeed · 7abbeed
1 parent bf5c79e
commit 7abbeed
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Showing 3 changed files with 23 additions and 7 deletions.
diff --git a/src/libcmd/repl-interacter.cc b/src/libcmd/repl-interacter.cc
@@ -1,5 +1,3 @@
-#include "file-system.hh"
-#include "libcmd/repl.hh"
 #include <cstdio>
 
 #ifdef USE_READLINE
@@ -19,6 +17,8 @@ extern "C" {
 #include "signals.hh"
 #include "finally.hh"
 #include "repl-interacter.hh"
+#include "file-system.hh"
+#include "libcmd/repl.hh"
 
 namespace nix {
 
@@ -124,7 +124,18 @@ ReadlineLikeInteracter::Guard ReadlineLikeInteracter::init(detail::ReplCompleter
     return restoreRepl;
 }
 
-bool ReadlineLikeInteracter::getLine(std::string & input, const std::string & prompt)
+static constexpr const char * promptForType(ReplPromptType promptType)
+{
+    switch (promptType) {
+    case ReplPromptType::ReplPrompt:
+        return "nix-repl> ";
+    case ReplPromptType::ContinuationPrompt:
+        return "          ";
+    }
+    assert(false);
+}
+
+bool ReadlineLikeInteracter::getLine(std::string & input, ReplPromptType promptType)
 {
     struct sigaction act, old;
     sigset_t savedSignalMask, set;
@@ -151,7 +162,7 @@ bool ReadlineLikeInteracter::getLine(std::string & input, const std::string & pr
 
     setupSignals();
     Finally resetTerminal([&]() { rl_deprep_terminal(); });
-    char * s = readline(prompt.c_str());
+    char * s = readline(promptForType(promptType));
     Finally doFree([&]() { free(s); });
     restoreSignals();
 

diff --git a/src/libcmd/repl-interacter.hh b/src/libcmd/repl-interacter.hh
@@ -7,14 +7,19 @@
 #include <string>
 
 namespace nix {
+enum class ReplPromptType {
+    ReplPrompt,
+    ContinuationPrompt,
+};
+
 class ReplInteracter
 {
 public:
     using Guard = Finally<std::function<void()>>;
 
     virtual Guard init(detail::ReplCompleterMixin * repl) = 0;
     /** Returns a boolean of whether the interacter got EOF */
-    virtual bool getLine(std::string & input, const std::string & prompt) = 0;
+    virtual bool getLine(std::string & input, ReplPromptType promptType) = 0;
     virtual ~ReplInteracter(){};
 };
 
@@ -27,7 +32,7 @@ public:
     {
     }
     virtual Guard init(detail::ReplCompleterMixin * repl) override;
-    virtual bool getLine(std::string & input, const std::string & prompt) override;
+    virtual bool getLine(std::string & input, ReplPromptType promptType) override;
     virtual ~ReadlineLikeInteracter() override;
 };
 

diff --git a/src/libcmd/repl.cc b/src/libcmd/repl.cc
@@ -197,7 +197,7 @@ ReplExitStatus NixRepl::mainLoop()
         logger->pause();
         // When continuing input from previous lines, don't print a prompt, just align to the same
         // number of chars as the prompt.
-        if (!interacter->getLine(input, input.empty() ? "nix-repl> " : "          ")) {
+        if (!interacter->getLine(input, input.empty() ? ReplPromptType::ReplPrompt : ReplPromptType::ContinuationPrompt)) {
             // Ctrl-D should exit the debugger.
             state->debugStop = false;
             logger->cout("");